This invention relates to a heatable hair curler. More particularly, this invention relates to a hair curler composed of material that can be easily heated in a microwave oven and retain its heat for a sufficient period of time to effect hair curling.
Hair curlers in common use are generally cylindrical spools having hollow cores that are heated by placing the spools over electrically heated posts. Such curlers require lengthy heat-up times and require specialized heaters.
More recently, it has been suggested to use hair curlers designed to be heated in a microwave oven in order to speed up the heating process.
For example, U.S. Pat. No. 4,538,630 discloses a plastic spool-type hair curler that can be heated in a microwave oven where the curler contains a "lossy dielectric material" to assist in the heating. The "lossy dielectric material" is described as being a ferrite material. The spool also contains a heat sink material, such as waxes, caustic soda, and metal salts.
U.S. Pat. No. 4,710,609 discloses a plastic spool-type hair curler that can be heated in a microwave oven where the spool has a mass of wicking material, such as foam rubber, to which water is added. Excess steam generated during microwave heating is vented to prevent explosions.